When an engine generates a power, intake air is guided to a combustion chamber and a combustible substance is burned in the combustion chamber. A thermal energy generated by the burning of the combustible substance is converted into a mechanical energy. By the burning of the combustible substance, the temperature in the vicinity of the combustion chamber is raised greatly.
On the other hand, it is proposed to activate the intake air through a discharge in order to carry out promotion of the burning of the combustible substance or the like. Patent Document 1 is taken as an example. In Patent Document 1, an electrode is provided close to an inlet of an intake manifold and a pulse voltage is applied to the electrode.
When the electrode is moved away from the combustion chamber, the activated intake air tends to be deactivated. For this reason, the electrode is desirably caused to approach the combustion engine. When the electrode is caused to approach the combustion chamber, the electrode is disposed at a high temperature.
Although Patent Documents 2 and 3 are not intended for the solution of problems to be solved by the present invention, they disclose matters related to the present invention.
Patent Document 2 describes a pulse generating circuit of an induction energy storage type in which an inductor and a primary winding of a transformer are connected in parallel. Patent Document 2 describes that the excitation inductance of a primary winding of a transformer is higher than the excitation inductance of an inductor.
Patent Document 3 describes the necessity of heat radiation of a semiconductor switching device.